Allocated but unannounced space
Every block here was allocated or assigned by a regional internet registry, and none of them appeared in any routing table we collected at our last snapshot — neither as a route of their own, nor covered by a larger announcement, nor carved up into more specifics.
“Unannounced” does not mean “unused”
Plenty of allocated space is deliberately kept off the public internet: private interconnects, lab and lawful-intercept ranges, networks reachable only inside one operator, and space held in reserve. Some of it is announced somewhere our collectors cannot see, which is a limit of our vantage points rather than a fact about the block.
It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today. Nothing on this page means a block is unallocated, available, or free to announce.
Browse by registry
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Countries with the most unannounced blocks, largest first.
Unannounced blocks in United States
27,021 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 204.68.250.0/24 | 256 | ARIN |  US | 26th Aug 1994 |
| 204.68.251.0/24 | 256 | ARIN | US | 26th Aug 1994 |
| 204.68.252.0/24 | 256 | ARIN | US | 26th Aug 1994 |
| 204.68.253.0/24 | 256 | ARIN | US | 26th Aug 1994 |
| 204.68.8.0/21 | 2k | ARIN | US | 1st Jul 1994 |
| 204.69.128.0/24 | 256 | ARIN | US | 16th Aug 1994 |
| 204.69.129.0/24 | 256 | ARIN | US | 16th Aug 1994 |
| 204.69.130.0/24 | 256 | ARIN | US | 16th Aug 1994 |
| 204.69.134.0/24 | 256 | ARIN | US | 22nd Aug 1994 |
| 204.69.135.0/24 | 256 | ARIN | US | 22nd Aug 1994 |
| 204.69.136.0/23 | 512 | ARIN | US | 22nd Aug 1994 |
| 204.69.138.0/24 | 256 | ARIN | US | 22nd Aug 1994 |
| 204.69.139.0/24 | 256 | ARIN | US | 30th Oct 2017 |
| 204.69.140.0/23 | 512 | ARIN | US | 30th Oct 2017 |
| 204.69.142.0/24 | 256 | ARIN | US | 22nd Aug 1994 |
| 204.69.143.0/24 | 256 | ARIN | US | 22nd Aug 1994 |
| 204.69.144.0/24 | 256 | ARIN | US | 7th Feb 2017 |
| 204.69.151.0/24 | 256 | ARIN | US | 22nd Aug 1994 |
| 204.69.153.0/24 | 256 | ARIN | US | 22nd Aug 1994 |
| 204.69.154.0/23 | 512 | ARIN | US | 21st Jun 2011 |
| 204.69.156.0/24 | 256 | ARIN | US | 23rd Dec 1996 |
| 204.69.157.0/24 | 256 | ARIN | US | 22nd Aug 1994 |
| 204.69.158.0/23 | 512 | ARIN | US | 22nd Aug 1994 |
| 204.69.160.0/23 | 512 | ARIN | US | 22nd Aug 1994 |
| 204.69.162.0/24 | 256 | ARIN | US | 22nd Aug 1994 |
| 204.69.163.0/24 | 256 | ARIN | US | 22nd Aug 1994 |
| 204.69.164.0/23 | 512 | ARIN | US | 22nd Aug 1994 |
| 204.69.169.0/24 | 256 | ARIN | US | 23rd Aug 1994 |
| 204.69.170.0/24 | 256 | ARIN | US | 23rd Aug 1994 |
| 204.69.172.0/22 | 1k | ARIN | US | 23rd Aug 1994 |
| 204.69.176.0/24 | 256 | ARIN | US | 23rd Aug 1994 |
| 204.69.177.0/24 | 256 | ARIN | US | 23rd Aug 1994 |
| 204.69.178.0/24 | 256 | ARIN | US | 23rd Aug 1994 |
| 204.69.179.0/24 | 256 | ARIN | US | 14th Jun 2023 |
| 204.69.180.0/24 | 256 | ARIN | US | 23rd Aug 1994 |
| 204.69.183.0/24 | 256 | ARIN | US | 23rd Aug 1994 |
| 204.69.184.0/24 | 256 | ARIN | US | 23rd Aug 1994 |
| 204.69.195.0/24 | 256 | ARIN | US | 24th Aug 1994 |
| 204.69.196.0/24 | 256 | ARIN | US | 24th Aug 1994 |
| 204.69.197.0/24 | 256 | ARIN | US | 24th Aug 1994 |
| 204.69.202.0/24 | 256 | ARIN | US | 24th Aug 1994 |
| 204.69.209.0/24 | 256 | ARIN | US | 24th Aug 1994 |
| 204.69.210.0/24 | 256 | ARIN | US | 10th Nov 2011 |
| 204.69.211.0/24 | 256 | ARIN | US | 25th Aug 1994 |
| 204.69.212.0/24 | 256 | ARIN | US | 26th Aug 1994 |
| 204.69.213.0/24 | 256 | ARIN | US | 26th Aug 1994 |
| 204.69.216.0/24 | 256 | ARIN | US | 26th Aug 1994 |
| 204.69.222.0/24 | 256 | ARIN | US | 26th Aug 1994 |
| 204.69.223.0/24 | 256 | ARIN | US | 26th Aug 1994 |
| 204.69.224.0/24 | 256 | ARIN | US | 26th Aug 1994 |